Speed Vs Power

[windwalker099]

There is the concept of "impulse" which is the momentum transfer into the target, it is the integral of force over "contact time". Unless your body is begind, you might get a weak impulse but with high peak force.

So we have two parameters.
- PEAK force
- Total energytransfer (or impulse)
View attachment 32634

Waves, also another way of transferring momentum..

@PhotonGuy

It works like this, the faster your hand or foot goes the harder it will hit, that's quite obvious. Just like how in Baseball a fastball pitch is going to hit the catcher's glove harder than a curve ball. Why? Because the fastball is faster than the curveball, therefore it hits harder when it lands in the catcher's glove. By the same concept the faster your punch or kick goes the harder it will hit when it hits your opponent, so speed is power.

Feel it depends on the method used for momentum transfer, how the momentum is transferred,
and what is interacting during the transfer.

This characteristic of a wave as an energy transport phenomenon distinguishes waves from other types of phenomenon.

"This characteristic of a wave as an energy transport phenomenon distinguishes waves from other types of phenomenon. Consider a common phenomenon observed at a softball game - the collision of a bat with a ball. A batter is able to transport energy from her to the softball by means of a bat.

The batter applies a force to the bat, thus imparting energy to the bat in the form of kinetic energy. The bat then carries this energy to the softball and transports the energy to the softball upon collision. In this example, a bat is used to transport energy from the player to the softball."

 

[Fungus]

Waves, also another way of transferring momentum..

Yes sure. but the picture with the impulse as force over time during the contact time to the target would be a universally valid physical picture.

It is independent of how the momentum of the limb is generated, it is just the simple physics picture.

I associate waves as the wave motion that exists in kinetic linking, and that can if done right (in phase with timing) increase both peak force and total impulse. In the "end of the wave", at the target there is a similar impulse no matter how your body and limbs has generated it. But they way it's done will influence the shape of the impulse. So there is indeed an impulse transfer also in wave motion.

 

[windwalker099]

. But they way it's done will influence the shape of the impulse. So there is indeed an impulse transfer also in wave motion.

The issue wasn't whether a wave can transfer momentum as an impulse. Rather, the focus was on showing that momentum can be transferred in different ways. Depending on the method used, it can influence how one perceives the process and the approach being applied.



The OP

My primary art is Karate and therefore Im posting this in the Karate folder but this same concept can be applied to any striking art. So anyway, I've heard talk about people who have tremendous speed but not much power which I find a bit confusing. If you've got speed you're going to have power. Why? Because speed is power. The more speed you've got the more power you've got.

His example

It works like this, the faster your hand or foot goes the harder it will hit, that's quite obvious. Just like how in Baseball a fastball pitch is going to hit the catcher's glove harder than a curve ball. Why? Because the fastball is faster than the curveball, therefore it hits harder when it lands in the catcher's glove. By the same concept the faster your punch or kick goes the harder it will hit when it hits your opponent, so speed is power.

He conflates 'speed' with the transfer of momentum in the form of kinetic energy.

 

[Fungus]

That's when you add mass into the equation, but the mass of your hand or foot doesn't change so if you want to gain power it would make sense to work on stuff that you can change.

But the "effective mass" is more than just your bare limb mass. You can for some attackes increase the "effective mass" behind the attack but rooting into the ground, and make your body push your arm forwards.

The example of walking into a "stop punch" is a great example. Here, if the rooting into the ground is good, the efffective mass is huge!

 

[PhotonGuy]

But the "effective mass" is more than just your bare limb mass. You can for some attackes increase the "effective mass" behind the attack but rooting into the ground, and make your body push your arm forwards.

The example of walking into a "stop punch" is a great example. Here, if the rooting into the ground is good, the efffective mass is huge!

I see what you mean but I would think your strike would go faster when you increase the effective mass the way you describe. It's like shooting a gun from a moving vehicle, if you shoot it in the same direction the vehicle is going, verses shooting while standing still. In the case where you're shooting the gun from a moving vehicle the bullet will be going faster than if you shoot it while standing still because you're adding the vehicle's speed to the bullet.

 

[Badhabits]

I see what you mean but I would think your strike would go faster when you increase the effective mass the way you describe. It's like shooting a gun from a moving vehicle, if you shoot it in the same direction the vehicle is going, verses shooting while standing still. In the case where you're shooting the gun from a moving vehicle the bullet will be going faster than if you shoot it while standing still because you're adding the vehicle's speed to the bullet.

It would! That's part of what your body is doing when you punch, sequentially. The hips- there's a lot of talk about how we move our hips to move our mass to generate momentum. But the hips also act as an accelerator. All the moving parts in say a reverse punch, from the foot/ground up are acting as an accelerator, not just moving mass. Each part- foot then leg then hips then....adds acceleration to what came before it. The end of the chain (fist) is riding on all the acceleration all those parts of the body have produced. This is one of the things all that endless marching up and down the dojo doing kihon reverse punches is trying to teach. You straighten your rear leg, your mass is now in motion. Then you thrust the hips, that accelerates what's already moving.

 

[Kung Fu Wang]

you're shooting the gun from a moving vehicle the bullet will be going faster than if you shoot it while standing still because you're adding the vehicle's speed to the bullet.

This is why dynamic punch (punch with footwork) is more powerful/advance than static punch.

 

[Same Trick]

. It's like shooting a gun from a moving vehicle, if you shoot it in the same direction the vehicle is going, verses shooting while standing still. In the case where you're shooting the gun from a moving vehicle the bullet will be going faster than if you shoot it while standing still because you're adding the vehicle's speed to the bullet.

Is it really so ? It probably is, but something to it sounds missing, or something like that ?

 

[HighKick]

I see what you mean but I would think your strike would go faster when you increase the effective mass the way you describe. It's like shooting a gun from a moving vehicle, if you shoot it in the same direction the vehicle is going, verses shooting while standing still. In the case where you're shooting the gun from a moving vehicle the bullet will be going faster than if you shoot it while standing still because you're adding the vehicle's speed to the bullet.

I think you need to do a little research: How Stuff Works

 

[PhotonGuy]

I think you need to do a little research: How Stuff Works

Im talking about in reference to a stationary object, such as a deer that's standing still. Lets say you're shooting at the stationary deer from the bed of a pickup truck while the truck is moving towards it, I would not recommend really doing this as I believe in most cases its illegal to hunt from vehicles but for the sake of science we can discuss it. Also most deer are not going to just stand still while a truck is coming towards them, let alone while being shot at, but again for science's sake we can discuss it. From the deer's perspective the bullet will be moving at the speed of the bullet plus the speed of the truck.

Now, lets say you're shooting at the deer while you're standing on the ground still, the bullet from the deers perspective will only be going at its ordinary speed without the speed of the truck added in because in this case you're not shooting from a moving truck you're shooting from a stationary position. So from the deer's perspective the bullet will be going faster if you shoot from the truck than if you shoot from a stationary position.

By the same token, if you punch towards an opponent, your hand is going to be going faster when you put your hips and the rest of your body into it than if you just punch with your arm, without putting the rest of your body into it, from your opponent's perspective.

 

[marvin8]

By the same token, if you punch towards an opponent, your hand is going to be going faster when you put your hips and the rest of your body into it than if you just punch with your arm, without putting the rest of your body into it, from your opponent's perspective.

What evidence do you have to support this? Studies have shown the opposite.

Excerpts from "Hand Speed Measurements in Boxing:"

"Not every punch has to be as fast as possible. Sometimes fast lead hand punches are used to break through the opponent’s defence in order to strike him with a powerful rear hand punch. With regards to technique the lead hand punch (jab) is different from the rear hand punch (cross). The jab is a fast but weak blow, delivered from the front hand...

In most cases, jabs had a higher velocity than the cross."

 

[isshinryuronin]

if you punch towards an opponent, your hand is going to be going faster when you put your hips and the rest of your body into it than if you just punch with your arm

You are missing an important point. The hip rotation is slower than the arm extension. This means in order to for the hips to add to their synergy to the punch speed their movement must be initiated prior to the punch being launched. In other words, the arm punching motion must wait for the hips. This time lag means the entire punching process with the hips will be slower than a punch without the hip rotation.

 

[Kung Fu Wang]

if you punch towards an opponent, your hand is going to be going faster when you put your hips and the rest of your body into it than if you just punch with your arm, without putting the rest of your body into it, from your opponent's perspective.

In theory, you can punch with "body chase arm":

- Your hand land on your opponent first.
- Your elbow follows.
- Your shoulder follows.
- Your body follows.

In reality, I don't know how effective this kind of punch can be.

To find a balance between power and speed is always the big challenge in MA. If your opponent keeps moving toward your side door, your powerful cross may never have a chance to punch out.

 

[windwalker099]

In reality, I don't know how effective this kind of punch can be.

To find a balance between power and speed is always the big challenge in MA. If your opponent keeps moving toward your side door, your powerful cross may never have a chance to punch out.

Do you feel there is no difference between what is called Jin (勁) and the Kinetic Chain, or is Jin (勁) not something you use to describe different types of force?

 

[Wing Woo Gar]

You need power (F) for speed, and the more mass (m) you're trying to accelerate (a) in the strike, the more force one needs to be "speedy".

F = m * a

If you want your "F" to be a high number, you need to be transfering your "m" with as much "a" as possible.

But not everyone has the same mass. The solution in competition? Weight divisions.

Thank you. I was hoping someone would just use the equation with proper terminology.

 

[Wing Woo Gar]

False. Power = Force x Velocity: This physics formula clearly shows that power requires both force (strength) and velocity (speed). An arm punch (e.g., jab) can be faster than a whole body punch (e.g., rear hand cross) but less powerful.

Punch Force - The Science Behind The Punch

Punch Force | Boxing | Strength and Conditioning | Sport Science | MMA

boxingscience.co.uk

Velocity is not the proper term. Acceleration is the proper term.

 

[Wing Woo Gar]

False. Power = Force x Velocity: This physics formula clearly shows that power requires both force (strength) and velocity (speed). An arm punch (e.g., jab) can be faster than a whole body punch (e.g., rear hand cross) but less powerful.

Punch Force - The Science Behind The Punch

Punch Force | Boxing | Strength and Conditioning | Sport Science | MMA

boxingscience.co.uk

…because the velocity is not constant in the trajectory.

 

[Wing Woo Gar]

I see. What I think of when I watch the videos is a 9mm Uzi vs a .270 bolt action rifle. An Uzi has a much faster rate of fire as it's a full automatic as opposed to the .270 which has a very slow rate of fire as you have to work the bolt in between each shot. However, the .270 has a much higher muzzle velocity, a .270 slug can have muzzle velocities of over 3500 fps, much faster than that of a 9mm, and its going to do much more damage, a .270 can take down medium and even large game, not something a 9mm is effective at.

So the 9mm has a faster rate of fire, but the ,270 has a higher muzzle velocity and more power, that's how I see the comparison of the two sets of videos you provide.

Rate of fire is irrelevant. The potential force of a given bullet depends upon efficiency of transfer, if the bullet fully penetrates the target and exits, for instance, much of the force was not transferred to the target. A .270 has an approximately 130 grain weight projectile traveling 3,060 ft/second at about 2700 ft lbs of force. A 9mm has an approximately 124 grain weight projectile traveling 900-1300 ft/second at about 350 ft lbs of force. I’m not sure this is the best analogy given the way ballistics works.

 

[Wing Woo Gar]

False. Power = Force x Velocity: This physics formula clearly shows that power requires both force (strength) and velocity (speed). An arm punch (e.g., jab) can be faster than a whole body punch (e.g., rear hand cross) but less powerful.

Punch Force - The Science Behind The Punch

Punch Force | Boxing | Strength and Conditioning | Sport Science | MMA

boxingscience.co.uk

“The science behind the punch” doesn’t even seem to know the basic physics equation for force and it really chaps my hide!

 

[Kung Fu Wang]

Do you feel there is no difference between what is called Jin (勁) and the Kinetic Chain, or is Jin (勁) not something you use to describe different types of force?

My definition of Jin is compress/release. Human body is like 3 separate springs. without training each spring can be compressed and released separately. With training, all 3 springs can be compressed at the same time and then release at the same time - body unification. If you can achieve body unification, you have Jin, otherwise, you don't have Jin.